This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. For assessment of human T cell responses to influenza A and B viruses, we have constructed a large panel of replication-restricted, recombinant vesicular stomatitis viruses, each expressing a single protein from a variety of influenza strains. The complete panel covers the HA and NA proteins from influenza vaccine strains used from 2000-2011, as well as the internal components of the A/California/04/09 strain from the recent pandemic, the PR8 strain that is used for production of the conventional vaccine, and the A/Ann Arbor/06/60 strain that is used for the production of the live-attenuated FluMist vaccine. We are using these to measure T cell responses in 60 donors who were vaccinated during the 2010-2011 season. In general, CD8 T cell responses to vaccination have been low-to-undetectable, a result that was not unexpected, especially for the conventional inactivated vaccine. In contrast, CD4 T cell responses are more frequent, with a response range of 0-631 per million CD4 cells.